Self-balancing device for turbines.



F. LJUNGSTRUM.

' SELF BALANCING DEVICE FOR TURBINES.

APPLICATION FILED JULY 26, 1913..

1,11 1,312, Patentd Sept. 22, 1914.

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WITNESSES: INVEN T0]? nrakur.

UNITED STATES PATENT can on; I;

FREDRIK L'JUNes'TRomoF STOCKHOLM, SWEDEN, assreisoifiiro' AKTI EBOLAGE'l- LJUNGSTRfiMS aneruamnor LI'L EH' ME s'wE'DEn'Q SELF-BALANCING DEVICE non TURBINEs.

site Wall of the casing, these surfaces being.

provided with labyrinth-packings in the form of concentric rings and grooves, entering into each other, in order to minimize the quantity of balancing steam. The steam in this case is caused to pass in a Wave-like If however, the cross area of the steam path at the labypath-beyond the ring edges.

rinth ring edges is altered due to an axial displacement of the turbine dis'ks, a sudden alteration of the steam pressure occurs, as

all the passages are simultaneously opened in the same degree. Hereby axial vibrations arise, which can be eliminated only with difliculty. To avoid this disadvantage the labyrinth packings, according to the present invention, are constructed in such a .way, that at the axial mutual displacement of the rings and grooves, all their passages will not be altered simultaneously, but the packings are successively opened or closed. This is attained by the ring edges lying on a conical or step-formed line, that is to say, they have not all the same height, consequently a wedge shaped path is produced, presenting greater resistance for the steam, and the expansion of the steam and the decrease of the tension of same will be greater.

Different embodiments of the invention are shown in longitudinal section in Figures 1, 2 and 3 of the accompanying drawing.

a indicates the turbine wheel or disk, carrying the blades (Z, and 6 indicates a station ary disk, arranged opposite the disk at. The

disk (1 and I) carry the concentric packing rings e, e and c, of which 6 and e are shaped so as to act in" opposite directions, as at the movement of the disk (1 to the right Specificaticnpf Letters Patent. Application fiiednii as,

the passages at e are altered, while at the movement of the disk (1 to the left the passages at eare altered. According to the present invention the rings or ribs 6 and e are now shaped in such a way, that all of them will not be brought into or out of action simultaneously, but at a'movementt of .the disk. at to the l'eft the packing rings 6 are opened successively and at a movement of said disk to the right the packing rings 0 are similarly opened. In the embodiment shown this is attained by the packing rings. e and e having difi'erent height, as their edges lie on a conical surface, while the edges of the rings 0 lie in the same plane.

Fig. 2 shows an embodiment, in which the height of the rings 6 is irregular, so that the edges thereof do not lie on a conical surface. The operation corresponds however to that of the device according to Fig. 1.

According to Fig. 3 the rings 2 all have the sameheight, while the rings a are of different height. I Having thus fully described my invention, .what I claimas new, and desire to secure by Letters Patent, is:

1. In a steam turbine, .a rotary member, a. stationary member, and a plurality of packing ribs on said rotary member adapted to cooperate with a plurality of grooves Patented Sept 22,1914. I I

formed on said stationary member and to varying cross-section the packing ribs being of varying depth relatively to the grooves in the stationary member.

3. A steam turbine comprising a stationary disk and a rotary disk having two series of annular ribs, cooperating with grooves in said stationary disk to constitute two series of packing ribsand to form a passagefor the steam, one series of ribs being adapted to become successively opened upon the axial displacement of the rotary disk in the one In testimony whereof I have afiixed my d-irgction alnllg the other sgries being adapted signature in presence of two Witnesses. to eoome ewise opene successivel u on the axial displacement of the rotary isli in FREDRIK LJUNGSTBOM' 5 the opposite direction the acking ribs being Witnesses:

of; varying depth relativefiy to the grooves HARRY ALBIHN, in the stationary disk.- F. BERGMAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of ,Iatents,

' Washington, D. 0. 

